This invention relates to a roller folding head.
Such roller folding heads, which are coupled with a robotic arm and are guided by the arm, are used, e.g., in the automobile industry in order to connect sheet metal together by means of folding operations. One area of application is, for example, the connection of the frame of a sliding roof with the edge of an opening in the roof of a vehicle.
A roller folding head that is suitable for such an operation must be adapted to the respective space requirements in the individual case and may not introduce any forces into the body of the vehicle during the folding operation. In addition, there should be as few swapping operations as possible.
The invention provides for solving the problem a roller folding head for fastening to a robotic arm with two pairs of rollers, each pair of rollers comprising a pressure roller and a counter-roller, both of which interact to bend a flange at a specific angle along a folding line, and with a base body and a carriage that can slide along the base body, the pressure rollers being mounted on the carriage so as to rotate.
Since, according to the above, two pairs of rollers are disposed at the roller folding head, at least two successive folding operations can be carried out. By means of the carriage, to which the pressure rollers are fastened, the pressure rollers are moved into the respective working position.
The two flanges, which are supposed to be connected together by means of the folding operation, are, first of all, parallel to each other, the one flange projecting beyond the other. The projecting segment of the one flange is gradually beaded 180° about the other flange in several steps. To carry out the first step, the pressure roller of the first pair of rollers has a conically expanding folding segment, which is forced against the projecting segment and bends this projecting segment to about 45°. So that the counter-roller of this pair of rollers can be guided behind the bent-over segment, it is pivot-mounted on another carriage which can be moved relative to the base body. The counter-roller of the second pair of rollers takes over the beading operation at another 45° and, therefore, does not have to be held moveably at the base body. Rather it is mounted at the base body in such a manner that it cannot slide.
Preferably the two carriages are arranged at the base body in such a manner that they can be moved perpendicularly in opposite directions. The result is a compact construction of the roller folding head.
It is true that each pair of rollers can be formed by one pressure roller and one counter-roller each, both of which are assigned only to this pair. Hence, four pairs of rollers yield eight individual rollers. To reduce the number of rollers, it is provided that one pressure roller can be assigned to any arbitrary counter-roller to form a pair of rollers. Thus, the system of roller pairs can comprise, for example, two pressure rollers and four counter-rollers, where one of the pressure rollers interacts in succession with three of the counter-rollers.
Preferably these counter-rollers are coupled with one revolver head, which is connected to the base body.
Secondly, the invention relates to a method for folding a flange in four steps, wherein at least three different pairs of rollers are used with the goal being a curl of 180°.
As to be explained in detail below, the first pair of rollers can be definitely used both for the first and for the final fourth folding step. In principle two procedures are possible. First, two roller folding heads with different pairs of rollers can be used. Secondly, a single roller folding head can be used, where the counter-roller of a pair of rollers can be swapped by means of a changing device so that a total of four different pairs of rollers is conceivable.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.